Make sure that the front cover is closed and the power cord is plugged in.
Hold down Go as you press to turn on the machine. Keep Go pressed down until the Toner, Drum, and Paper LEDs light up.
Release Go. Make sure that all the LEDs turn off.
Press Go eight times. Make sure that all the LEDs light up to indicate the machine has been reset to its factory default settings (except the Interface and Local Language settings).